Watch strap buckle



FIG. 1 is a perspective view of a watch strap buckle, showing our new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a right elevational view thereof;

FIG. 5 is a left elevational view thereof;

FIG. 6 is a front elevational view thereof;

FIG. 7 is a back elevational view thereof;

FIG. 8 is a perspective view thereof in an environment in which it may be used; and,

FIG. 9 is a perspective view thereof in an environment in which it may be used.

The broken lines in the Figures show the the buckle strap pin and environment that form no part of the claimed design. 

CLAIM We claim the ornamental design for a watch strap buckle, as shown and described. 